Conventional barrier structures, laminates and coextrusions contain gas barrier materials, such as foil, polyamide, ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyethylene terephthalate (PET), and combinations of these materials with other resins. Such structures can be used in various applications, such as semi permeable membranes for the production of bladders for sportsgoods (including bladders for footwear, sports balls, seats, inner tubes and cushioning devices). However, these structures are relatively rigid, and do not provide elastomeric recovery properties, in addition to excellent barrier properties. Such structures are also frequently used in applications such as food packaging, where the package is discarded after opening and use. As a result, these structures and laminates are not designed to sustain significant levels of abuse and continued re-use for an extended period. There is a need for articles, such as films, with improved gas barrier properties, and with excellent elastomeric properties and physical abuse resistance, and which can be used for an extended periods. There is a further need for such articles for the manufacture of inner tubes and other bladder applications, which are operated at pressures higher than atmospheric pressure. Various applications use semi permeable membranes for the production of bladders for sportsgoods (including bladders for footwear, sports balls, seats, inner tubes and cushioning devices). The article of interest contains a super-gas which is prevented from permeating through the bladder membrane. However, there is a need for membranes that can be used as barriers to small molecular gases.
International Publication No. WO 2007/062669 discloses a tire comprising a carcass structure, which comprises at least one layer formed from a crosslinked elastomeric material having air barrier properties, and where said crosslinked elastomeric material is obtained by crosslinking an elastomeric composition comprising: (a) from 10 phr to 100 phr of at least one butyl rubber; (b) from 0 phr to 90 phr of at least one diene elastomeric polymer; (c) from 5 phr to 120 phr of at least one reinforcing filler; (d) from 2 phr to 20 phr of at least one copolymer of at least one ethylenically unsaturated carboxylic acid, or a derivative thereof, with at least one ethylenically unsaturated monomer, containing at least one polyoxyalkylene side chain (for example, see abstract).
U.S. Pat. No. 5,992,486 discloses a laminate suitable for use with a pneumatic tire having an inner liner or like air-impermeable layer capable of maintaining a requisite air pressure. One laminate includes laminated films and a rubber layer (R); the laminated films being made of a gas barrier layer (A) and an adhesive layer (B). The adhesive layer (B) is located on at least one side of the layer (A), and the layer (A) is formed of at least one member selected from polyamide resins, polyester resins, polyarylate resins, polyamide-based alloys and polyester-based alloys. The laminated films are irradiated, in at least one periphery, with an electron beam, and the adhesive layer (B) is heat-bonded to the rubber layer (R). Another laminate includes laminated films and a rubber layer (R); the laminated films being made of a rubber-adhering layer (D), an adhesive layer (B) and a gas barrier layer (A). The layers (D), (B) and (A) are laminated in this order, with a structure of at least three layers. The rubber-adhering layer (D) is formed of at least one polyolefin resin, the gas barrier layer (A) is formed of at least one member selected from polyamide resins, polyester resins, polyarylate resins, polyamide-based alloys and polyester-based alloys. The laminated films are irradiated in at least one periphery with an electron beam, and the rubber-adhering layer (D) is heat-bonded to the rubber layer (R) (see abstract).
U.S. Pat. No. 6,579,580 discloses a composite container having a barrier property, and comprising packaging material. The packaging material comprises a base material and a co-extruded laminate layered on the base material. The base material has a paper support, with an inner surface and an outer surface, and a polyolefin resin layer, attached on the outer surface of the paper support, and constituting an outermost layer of the container. The laminate consists of a polyolefin resin layer, a second adhesive layer, a barrier layer, a first adhesive layer, and another polyolefin resin layer, and is arranged in this order, and has five layers in total. The container is formed by co-extrusion of the respective fused resins onto the base material. The former polyolefin resin layer of the laminate is directly applied onto the inner surface of the paper support, the latter polyolefin resin layer of the laminate, constituting an innermost layer of the container, and the barrier layer comprising polyamide resin having an aromatic moiety (see abstract).
U.S. Pat. No. 6,139,931 discloses a multi-layer closure liner for carbonated beverage containers, and the like, which includes a gas barrier layer, a first tie layer on an upper surface of the gas barrier layer, a second tie layer on a lower surface of the gas barrier layer, a first polyolefinic resin layer on the upper surface of the first tie layer, and a second polyolefinic layer on the lower surface of the second tie layer. In the preferred embodiment, the gas barrier layer is ethylene vinyl alcohol copolymer (EVOH), the first and second tie layers are functionalized polyolefin, and the first and second polyolefinic resin layers are ethylene vinyl acetate (EVA). The layers defining the closure liner are preferably simultaneously formed using a co-extrusion process to prevent the gas barrier layer from being exposed to moisture (see abstract).
Japanese Patent Disclosure No. 2003-11288 discloses a multilayered structural that contains a resin composition (P) layer that contains a gas barrier resin (A), having the oxygen transmission rate of less than, or equal to, 500 mL·20 μm/m2·day·atm (20° C., 65%; RH), a thermoplastic resin (B) having a carbon-carbon double bond, and a transition metal salt (C); and a resin composition (R) layer that contains a drying agent (D), and a thermoplastic resin (E). The content of the drying agent is from 0.1 to 50 weight percent. The thermoplastic resin (B) may be a copolymer of an aromatic vinyl compound and a diene compound. The gas barrier resin (A) may be at least one resin selected from a polyvinyl alcohol, a polyamide or a polyacrylonitrile.
U.S. Pat. No. 6,524,712 discloses a multilayer film which has at least one first layer (1) of a thermoplastic polyurethane, at least one second layer (2) of a thermoplastic elastomer, and optionally a third layer (3) of a thermoplastic polyurethane. The ratio of the water vapor permeability level of the first layer (1) to the water vapor permeability level of the second layer (2), of the multilayer film, is at least two. When the optional third layer (3) is present in the multilayer film, the first and third layers enclose the second layer.
U.S. Pat. No. 5,941,286 discloses automotive filler tubes fabricated from laminated rubbery structure of selected fluoropolymeric materials laminated with a rubbery copolymer, like an epichlorohydrin elastomer, to provide a flexible tubular article, permitting only negligible escape of confined volatile hydrocarbons. A FKM rubbery polymer forms a relatively thin inner layer in the tube, a THV polymer forms a relatively thin intermediate layer, and a relatively thick elastomeric polymer, e.g., ECO, forms a cover layer. In an alternative embodiment, a tube is formed from an inner layer of a THV fluoroplastic polymer and a cover layer of a relatively thick elastomeric polymer. The tubing is made by coextruding the FKM rubbery polymer and the THV fluoroplastic polymer, coating the THV fluoroplastic polymer layer with a binder, crosshead extruding the elastomeric polymer layer, and cutting the tubing to lengths. The lengths are given a partial cure in straight condition to cross-link the THV fluoroplastic layer to the FKM rubber polymer layer and to the elastomeric layer. The partially cured lengths of tubing are shaped and then fully cured.
French Patent Disclosure 2650777 (Abstract) discloses a flexible tubing having an inner tube made of a material of the NBR nitrile, PVC-nitrile NBR-PVC or hydrogenated HNBR nitrile rubber type and fluoroelastomers. An outer tube or protective layer, coextruded with the inner tube, is made of a material chosen from rubbers of the epichlorohydrin, chlorinated polyethylene CM, chlorosulphonated polyethylene CSM or ethylene acrylate type.
U.S. Publication No. 2002/0031628 discloses a flexure endurant composition of an elastomer reinforced with a continuous phase of microporous, expanded polytetrafluoroethylene (ePTFE) having a ratio of elastomer to PTFE of approximately 1:1 to 50:1, on a volume basis. Examples of common synthetic elastomers include silicones, urethanes, nitrile rubber, styrene-butadiene-styrene (SBR), chloroprene, phosphazenes, fluoroelastomers, perfluoroelastomers, perfluoropolyether elastomers, having a rubbery elastic modulus of less than 107 Pa.
U.S. Publication No. 2007/0141282 discloses a multi-layer composite that has at least one elastomer layer and at least one barrier layer. In various embodiments, the composite contains at least two elastomer layers, alternating with at least two barrier layers. In other embodiments, the composite comprises at least ten alternating barrier and elastomer layers. The barrier layer is made of an amorphous polymer, and is provided in the form of a film. Preferably, the amorphous polymer film has a gas transmittance rate (GTR) of less than 40 cc·mil/m2·day·atm; measured as nitrogen transmittance at 0% relative humidity at 23° C. Materials for the elastomeric layers include polyurethane elastomers, flexible polyolefins, styrenic thermoplastic elastomers, polyamide elastomers, polyamide-ether elastomers, ester-ether or ester-ester elastomers, flexible ionomers, thermoplastic vulcanizates, flexible poly(vinyl chloride) homopolymers and copolymers, and flexible acrylic polymers.
U.S. Publication No. 2007/0065616 discloses a flexible tubular article for transport of volatile hydrocarbons, permitting only negligible escape of such vapors, and comprising: (a) a relatively thin, inner layer of an elastomeric form of an FKM fluoropolymer, and (b) one of more relatively thin intermediate layers of a thermoplastic form of an THV fluoropolymer, extruded in tubular form over the inner FKM layer, and (c) a durable outer layer of an elastomeric polymer bonded to the outside surface of the intermediate layer and being coextensive therewith.
U.S. Pat. No. 4,776,909 discloses a coextrusion from rubber of hollow tubular structures with filament reinforcement for composites which can be formed into spliceless bodies for pneumatic tires. The composites can be formed from one, two, three or more rubber stocks and have portions or layers which can form the body plies, sidewalls, innerliners, stabilizer ply inserts, and, optionally, abrasion gum strips of tire bodies. Conventional tire sidewall rubber stocks typically have a rubber composition comprising the following types of rubbers in the percentage (by weight) ranges: NR, 20-50%; BR, 0-60%; SBR, 30-60%; and EPDM, 0-30%. A conventional tire body rubber stock typically has a rubber composition within the percentage (by weight) ranges: NR, 50-100%; BR, 30-60%; and SBR, 20-50%.
U.S. Pat. No. 5,049,220 discloses a method of preparing a pneumatic rubber tire having a decorative applique on the sidewall thereof, which comprises (a) applying the decorative applique to the sidewall of a cured tire, and (b) binding the decorative applique to the sidewall by the application of heat and pressure. The decorative applique comprises from about 25 weight percent to about 75 weight percent syndiotactic 1,2-polybutadiene, or blends of SPBD having melting points which are within the range of about 70° C. to about 160° C., and from about 25 weight percent to about 75 weight percent of at least one polydiene rubber, which is blended with the syndiotactic 1,2-polybutadiene, sulfur, zinc oxide and at least one pigment or colorant.
U.S. Pat. No. 4,967,818 discloses a method of preparing a pneumatic rubber tire having a decorative design on the sidewall thereof, which comprises (a) applying the decorative design to the sidewall of an uncured tire, and (b) curing the tire. The decorative design comprises from about 25 weight percent to about 75 weight percent syndiotactic 1,2-polybutadiene having a melting point, within the range of about 100° C. to about 160° C., and from about 25 weight percent to about 75 weight percent of at least one polydiene rubber, which is cocurable with said sydiotactic 1,2-polybutadiene, at least one pigment or colorant, sulfur, and zinc oxide.
U.S. Pat. No. 5,260,123 discloses block copolymers which comprise alternating blocks of (A) a polysiloxane; and (B) a copolymer of a 1,3-conjugated diene and a monovinyl aromatic compound. Cured elastomer compositions exhibiting surface release characteristics are obtained by curing a mixture comprising the above-described block copolymer in the presence of a curing system comprising a peroxide and sulfur. Multilayer elastomer structures useful in manufacturing articles from elastomeric materials also are described, wherein at least a portion of an outer layer of the multilayer elastomer structure has release characteristics and comprises the cured block copolymers of the present invention.
U.S. Pat. No. 5,957,164 discloses a barrier hose comprising an innermost tube of a thermoplastic vulcanizate. The innermost tube of thermoplastic vulcanizate is coextruded with a flexible polyamide barrier material as a second tube. A backing of thermoset rubber is extruded or calendared over the polyamide barrier tube. A reinforcement layer follows which is then covered with an EPDM outer cover.
U.S. Patent 2002/0179647 discloses a hydration system for providing fluid to a user. The system comprises a bladder, configured to hold a fluid, which comprises an outer layer of a fluorinated rubber composite. An inner bladder layer may comprise a thermoplastic polymer, and an outer bladder, encompassing the inner bladder, may comprise a fluorinated rubber. The inner bladder layer may be comprised of thermoplastic polyurethane. The outer bladder may be comprised of a multiplayer laminate of the fluorinated rubber layer, a polyamide reinforcement layer, and a thermoplastic polymer layer.
Additional films, laminates and/or tubes are described in International Publications Nos. WO2004/050358, WO2005/068191, WO2002/29299 and WO2008/091847; Japanese Patent Application Disclosure Nos. JP2004268321, JP2005335309, JP 6-328629, JP3288084A (Abstract), JP3049937A (Abstract) and JP2024137A (Abstract); Japanese Patent Application Disclosure Bulletin Nos. JP 7-329252, JP 7-329261; Japanese Patent Application Nos. 8-145711, and H10-109781; U.S. Publication Nos. 2004/0105945, 2004/0103967 and US2005/0048236.
Butyl rubber has good barrier property for small molecular gases, and is typically used for inner tube applications. Current applications use a blend containing from 15% to 25% EPDM, and from 75% to 85% butyl rubber, to maintain acceptable barrier property and reduce cost. However, there is a need to further reduce butyl rubber usage, or replace butyl rubber with EPDM and/or other elastomeric polymers, to reduce cost. There is a further need for articles that achieve much better barrier properties than the incumbent articles prepared from conventional polymer blends, such as a butyl/EPDM blend. There is an additional need for articles with improved temperature and ozone resistance relative to the incumbent butyl/EPDM blend. These needs and others have been met by the following invention.